Yes, please! There are only a few resources for learning Choctaw, but having the learning organized through duolingo would be so helpful. I can imagine a collaboration with the Choctaw Nation of Oklahoma might be possible. http://www.choctawschool.com
My father spoke Choctaw (Chahta) as he was raised by my native american grandpa. But My father died a few years ago and I never had the opportunity to learn from him. Having a Choctaw course would be amazing.